This invention relates principally to a metal melt oven or furnace, and more particularly to a unique automatic metal flow tapper and flow control system for a metal melt oven or furnace.
When a metal melt oven or furnace (collectively “Melt Furnace”) is constructed, the Melt Furnace typically incorporates one or more plugged “tap” holes formed and positioned near the base of the melt zone to remove the melt from the furnace. When the molten metal is ready to be removed from the Melt Furnace, the plug or plugs are removed and the molten metal is allowed to flow freely out of the tap hole. It is also traditional that a trough or other similar conduit will be positioned below the level of the tap hole to gather and direct the molten metal away from the Melt Furnace. Alternately, a collection vessel may be positioned directly below the tap hole(s) to collect the molten metal as it exits the Melt Furnace.
Prior to the availability of automated tapping devices, the plugging and unplugging, i.e. “tapping”, of the tap holes in a Melt Furnace was conducted by an individual utilizing a manual tapper. Such manual tappers were constructed in a wide variety of configurations, but essentially consisted of a long pole with a pointed end used to tap and plug the tap hole. Despite the inherent dangers to the individual performing the tapping, this technique is still used in many operations yet today. Fortunately, automated tappers have been developed that remove the human element from too close contact with the furnace. One such automatic tapper is the Gillespie & Powers, Inc. Model 995. Automatic tappers are mechanisms that remotely force a tap hole plug in the tap hole to shut off metal flow from the furnace, and alternately remove the plug to allow the metal to flow out of the tap hole. Thus, automatic tappers provide binary control of the metal flow in an ON-OFF fashion. This is a relatively crude and inaccurate approach.
However, for many metal furnace operations, the rate molten metal flow out of the furnace through the tap hole or tap holes can be a critical process parameter, which may require constant monitoring and adjustment. In a simple example, for a continuous flow Aluminum Melt Furnace, the volume of the melt is essentially constant and the Aluminum melt flowing out of the Aluminum Melt Furnace therefore limits the throughput of the operation. Significantly, neither a traditional automatic tapper nor a manual tap rod is capable of easily or accurately controlling the metal flow out of a tap hole in a repeatable fashion. Hence, there is a need in the industry for a mechanism to provide more accurate and repeatable control of molten metal flow from a Melt Furnace tap hole while also having the capability to plug or entirely shut off the metal flow from the tap hole.
As will become evident in this disclosure, the present invention provides benefits over the existing art.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.